Method for making lube basestocks

ABSTRACT

A method to produce high quality lube oil products involving hydrotreating a waxy feed to produce a hydrotreated feed and subsequently hydroisomerizing and hydrodewaxing the hydrotreated waxy feed.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. patentapplication Ser. No. 10/342,600 filed Jan. 15, 2003, which is adivisional application of U.S. patent application Ser. No. 09/601,481filed Feb. 12, 1999, now U.S. Pat. No. 6,620,312, which claims benefitof international application number PCT/US99/03007 filed Feb. 12, 1999,which claims priority from U.S. Provisional Application No. 60/074,617filed Feb. 13, 1998.

FIELD OF THE INVENTION

[0002] The present invention is a method to produce high quality lubeoil products involving hydrotreating a waxy feed to produce ahydrotreated feed and subsequently hydroisomerizing and hydrodewaxingthe hydrotreated waxy feed.

BACKGROUND OF THE INVENTION

[0003] The hydroisomerization of wax and waxy feeds to liquid productsboiling in the lube oil boiling range and catalysts useful in suchpractice are well known in the literature. Preferred catalysts ingeneral comprise noble Group VIII metals on halogenated refractory metaloxide support, e.g. platinum on fluorided alumina. Other usefulcatalysts can include noble Group VIII metals on acidic refractory metaloxide support such as silica/alumina which has their acidity controlledby use of dopants such as yttria. As useful as hydroisomerizationprocesses may be, in general they do not achieve the final pour pointtarget without supplemental dewaxing, either catalytic or solvent.

[0004] Alternatively, hydrodewaxing using microporous materials is aprocess that can achieve low pour points, but properties such asViscosity Index (“VI”) tended to be lower than that achieved by solventdewaxing processes. Since the 1990's, zeolites possessing someisomerization function have been found to improve VI, but, bythemselves, may not produce a basestock and/or finished oil having allthe desired properties. For example, hydrotreated basestocks may have aresidual haze associated with limited reaction of the highest boilingparaffins. As well, volatility may not be as low as required for abasestock of a given viscosity, associated with a reaction mechanismfavoring lower molecular weight molecules in the feed. This may resultin a skewed distribution of product molecules.

[0005] It is likewise known that low temperature properties are highlydependent on processing schematics and catalyst. In general, thereexists a need in the art for improved catalysts and processing schemesto prepare basestocks sufficient to meet modern lubricant standards,particularly for motor oils. Such basestocks require superiorviscometric performance at both high and low temperatures as well as lowvolatilities.

SUMMARY OF THE INVENTION

[0006] The instant invention is directed at a method for producing alube oil lube basestock from a lube oil boiling range feedstreamcontaining at least about 50 wt. % wax, containing at least one polarcompound selected from sulfur and nitrogen compounds. The processcomprises:

[0007] a) contacting the lube oil boiling range feedstream with ahydrotreating catalyst in a first reaction stage operated underconditions effective at removing at least a portion of the at least onepolar compound from said lube oil boiling range feedstream to produce ahydrotreated feed;

[0008] b) contacting at least a portion of said hydrotreated feed withan amorphous hydroisomerization catalyst in a second reaction stageoperated under effective hydroisomerization conditions to produce asecond stage effluent; and

[0009] c) contacting at least a portion of said second stage effluentwith a hydrodewaxing catalyst in a third reaction stage operated underconditions effective for producing at least one lube oil basestockwherein said catalyst comprises at least one molecular sieve and anamorphous material having at least one active metal hydrogenationcomponent dispersed thereon.

[0010] In one embodiment, the amorphous material in the third reactionstage is selected from refractory metal oxides, refractory metal oxidesincluding a dopant, and mesoporous catalysts, wherein the amorphousmaterial of the dewaxing catalyst in the third reaction stage furthercomprises at least one active metal hydrogenation component dispersedthereon.

[0011] In another embodiment the process comprises:

[0012] a) contacting the lube oil boiling range feedstream with ahydrotreating catalyst in a first reaction stage operated underconditions effective at removing at least a portion of the at least onepolar compounds from said lube oil boiling range feedstream to produce ahydrotreated feed; and

[0013] b) contacting at least a portion of said hydrotreated feed with acatalyst system in a second reaction stage operated under conditionseffective at producing at least one lube oil boiling range basestockwherein said catalyst system comprises at least one first catalystselected from amorphous hydroisomerization catalyst and at least onesecond catalyst selected from hydrodewaxing catalysts comprising atleast one molecular sieve and an amorphous materials having at least oneactive metal hydrogenation component dispersed thereon.

DETAILED DESCRIPTION OF THE INSTANT INVENTION

[0014] The present invention is directed at a method of producing lubeoil basestocks from a lube oil boiling range feedstream containing atleast about 50 wt. % wax, and at least one polar compound selected fromthose containing sulfur or nitrogen. In one embodiment, a hydrotreatedfeed is produced by contacting the lube oil boiling range feedstreamwith a hydrotreating catalyst in a first reaction stage operated underconditions effective at removing at least a portion of the at least onepolar compound from the lube oil boiling range feedstream. At least aportion of the hydrotreated feed is subsequently contacted with ahydroisomerization catalyst in a second reaction stage to produce asecond stage effluent. At least a portion of the second stage effluentis subsequently contacted with a hydrodewaxing catalyst in a thirdreaction stage. The hydrodewaxing catalyst comprises at least onemolecular sieve and an amorphous material having at least one activemetal hydrogenation component dispersed thereon.

[0015] In another embodiment of the instant invention, the second andthird reaction stages appear as one reaction stage. In this embodiment,the hydrotreated feed is conducted to a second reaction stage operatedunder conditions effective at producing at least one lubricating oilbasestock. In the second reaction stage, the hydrotreated feed iscontacted with a catalyst system comprising at least one first catalystselected from amorphous hydroisomerization catalyst and at least onesecond catalyst selected from hydrodewaxing catalysts comprising atleast one molecular sieve and an amorphous material having at least oneactive metal hydrogenation component dispersed thereon.

[0016] In yet another embodiment, the amorphous material of thehydrodewaxing catalyst is selected from refractory metal oxides,refractory metal oxides including a dopant, and mesoporoushydroisomerization catalysts, wherein the second catalyst furthercomprises at least one active metal hydrogenation component dispersedthereon.

[0017] Lube oil boiling range feedstream suitable for use herein containat least about 50 wt. % wax, and at least one polar compound containingsulfur or nitrogen. These feedstreams typically have a 10% distillationpoint greater than 650° F. (343° C.), measured by ASTM D 86 or ASTM2887, and are derived from mineral or synthetic sources. The wax contentof the feedstock is at least about 50 wt. %, based on feedstock and canrange up to 100 wt. % wax. The high wax content also typically resultsin these feedstreams having high viscosity indexes of up to 200 or more.The wax content of a feed may be determined by nuclear magneticresonance spectroscopy (ASTM D5292), by correlative ndM methods (ASTMD3238) or by solvent means (ASTM D3235). The waxy feeds may be derivedfrom a number of sources such as oils derived from solvent refiningprocesses such as raffinates, partially solvent dewaxed oils,deasphalted oils, distillates, vacuum gas oils, coker gas oils, slackwaxes, foots oils and the like, Fischer-Tropsch waxes and anycombinations thereof. Preferred feeds are slack waxes andFischer-Tropsch waxes. Slack waxes are typically derived fromhydrocarbon feeds by solvent or propane dewaxing. Slack waxes containsome residual oil and are typically deoiled. Foots oils are derived fromdeoiled slack waxes. Fischer-Tropsch waxes are prepared by theFischer-Tropsch synthetic process.

[0018] These lube oil boiling range feedstreams can also typicallycontain at least one polar compound such as those containing sulfur ornitrogen, and mixtures thereof. Typically the concentration of nitrogenand sulfur polar compound are considered high by those skilled in theart. Lube oil boiling range feedstreams containing up to 0.2 wt. % ofnitrogen, based on feed and up to 3.0 wt. % of sulfur can be processedin the present process. Sulfur and nitrogen contents may be measured bystandard ASTM methods D5453 and D4629, respectively.

[0019] In the practice of the present invention, the above-describedlube oil boiling range feedstreams are contacted with a hydrotreatingcatalyst in a first reaction stage operated under conditions effectivefor removing at least a portion of the at least one polar compound fromthe lube oil boiling range feedstream to produce a hydrotreated feed.Hydrotreating catalysts suitable for use herein are those containing atleast one Group VI metal and at least one Group VIII metal, and mixturesthereof. Preferred metals include nickel, tungsten, molybdenum, cobaltand mixtures thereof. These metals or mixtures of metals are typicallypresent as oxides or sulfides on refractory metal oxide supports. Themixture of metals may also be present as bulk metal catalysts whereinthe amount of metal is 30 wt. % or greater, based on catalyst. Suitablemetal oxide supports include oxides such as silica, alumina,silica-aluminas or titania, preferably alumina. Preferred aluminas areporous aluminas such as gamma or eta. It should be noted that bulkcatalysts typically do not include a support material, and the metalsare not present as an oxide or sulfide but as the metal itself. Thesecatalysts typically include metals within the range described above inrelation to bulk catalyst and at least one extrusion agent. The amountof metals for supported hydrotreating catalysts, either individually orin mixtures, ranges from about 0.5 to 35 wt. %, based on the catalyst.In the case of preferred mixtures of Group VIII metals with Group VImetals, the Group VIII metals are present in amounts of from 0.5 to 5wt. %, based on catalyst and the Group VI metals are present in amountsof from 5 to 30 wt. %. The amounts of metals may be measured by atomicabsorption spectroscopy, inductively coupled plasma-atomic emissionspectrometry or other methods specified by ASTM for individual metals.Non-limiting examples of suitable hydrotreating catalysts includeNebula™, RT-721, KF-840, KF-848, DN 190 and Sentinel™. Preferredhydrotreating catalysts are low acidity, high metals content catalystssuch as KF-848 (Akzo Nobel), DN-190 (Criterion catalysts) and RT 721(Akzo Nobel).

[0020] As stated above, the lube oil boiling range feedstreams usedherein are contacted with the above-described hydrotreating catalyst ina first reaction stage under conditions effective at removing at least aportion of at least one polar compound contained therein. By at least aportion of nitrogen polar compounds it is meant that contacting the lubeoil boiling range feedstream reduces the nitrogen content to a levelthat will not unacceptably impact downstream, in relation to the flow ofthe feedstream, catalysts. The nitrogen content is typically reduced tolower than about 25 wppm, preferably lower than about 10 wppm, morepreferably lower than about 5 wppm, and most preferably lower than about2 wppm. Likewise, by at least a portion of sulfur polar compounds it ismeant that contacting the lube oil boiling range feedstream reduces thesulfur content to a level that will not unacceptably impact thedownstream catalysts. The sulfur content is typically reduced to lowerthan about 20 wppm, preferably lower than about 10 wppm.

[0021] These hydrotreating conditions typically include temperatures offrom 150 to 400° C., preferably 200 to 350° C., a hydrogen partialpressure of from 1480 to 20786 kPa (200 to 3000 psig), preferably 2859to 13891 kPa (400 to 2000 psig), a space velocity of from 0.1 to 10liquid hourly space velocity (LHSV), preferably 0.1 to 5 LHSV, and ahydrogen to feed ratio of from 89 to 1780 m³/m³ (500 to 10000 scf/B),preferably 178 to 890 m³/m³.

[0022] At least a portion, preferably substantially all, of thehydrotreated feed from the first reaction stage is then contacted with ahydroisomerization catalyst in a second reaction stage operated undereffective hydroisomerization conditions to produce a second stageeffluent. Hydroisomerization catalysts suitable for use herein willtypically comprise a porous refractory metal oxide support such asalumina, silica-alumina, titania, zirconia, etc. which contains anadditional catalytic component selected from at least one of a Group VIB, Group VII B, Group VIII metals, preferably a Group VIII metal, morepreferably a noble Group VIII metal, most preferably platinum andpalladium present in an amount in the range of 0.1 to 5 wt. %,preferably 0.1 to 2 wt. % most preferably 0.3 to 1 wt. % and which alsomay contain promoters and/or dopants selected from the group consistingof halogen, phosphorous, boron, yttria, rare-earth oxides and magnesiapreferably halogen, yttria, magnesia, most preferably fluorine, yttria,magnesia. When halogen is used it is present in an amount in the range0.1 to 10 wt. %, preferably 0.1 to 5 wt. %, more preferably 0.1 to 2 wt.% most preferably 0.5 to 1.5 wt. %. If the metal component is Group VIB,non-noble metal Group VIII or mixture thereof, then the amount of metalcan be increased up to 30 wt. %.

[0023] For those catalysts which do not exhibit or demonstrate acidity,for example gamma-alumina, acidity can be imparted to the catalyst byuse of promoters such as fluorine, which are known to impart acidity,according to techniques well known in the art. Thus, the acidity of aplatinum on alumina catalyst can be very closely adjusted by controllingthe amount of fluorine incorporated into the catalyst. Similarly, thecatalyst particles can also comprise materials such as catalytic metalincorporated onto silica-alumina. The acidity of such a catalyst can beadjusted by careful control of the amount of silica incorporated intothe silica-alumina base or by starting with a high aciditysilica-alumina catalyst and reducing its acidity using mildly basicdopants such as yttria or magnesia, as taught in U.S. Pat. No. 5,254,518(Soled, McVicker, Gates and Miseo).

[0024] Effective hydroisomerization conditions are to be considered anyhydroisomerization conditions that when used in combination with theselected hydroisomerization condition operate to reduce the wax contentin the lube oil boiling range feedstream to below about 40 wt. %,preferably to about 35 wt. % to about 25 wt. %. These conditionstypically include temperatures between about 300° C. to about 400° C.,preferably about 300° C. to about 380° C., pressures between about 500to about 5000 psig (about 3.55 to about 34.5 mPa), preferably about 1000to about 2000 psig (about 7.0 to about 13.9 mPa), hydrogen treat gasrates of 500 to about 10,000 SCF H₂/B (about 89 to about 1780 m³/m³),preferably about 2,000 to about 5,000 SCF H₂/B (about 356 to about 890m³/m³), and liquid hourly space velocities (“LHSV”) of about 0.5 toabout 5 V/V/hr. preferably about 1 to 2 about V/V/hr, for a timesufficient to reduce the wax content in the feed to below about 40 wt.%, preferably to about 35 wt. % to about 25 wt. %.

[0025] At least a portion, preferably substantially all, of the secondstage effluent is subsequently contacted with a hydrodewaxing catalystin a third reaction stage to produce a lube oil basestock. Hydrodewaxingcatalysts suitable for use herein are those that comprise at least onemolecular sieve and an amorphous material having at least one activemetal hydrogenation component dispersed thereon at least one.

[0026] Molecular sieves suitable for use herein are be selected fromZSM22, ZSM-23, ZSM-35, ZSM-48, ZSM-57, SSZ-31, SAPO-11, SAPO-31,SAPO-41, MAPO-11, ECR-42, synthetic Ferrierites, and mixtures thereof.Preferred molecular sieves include ZSM-22, ZSM-23, ZSM-35, ZSM-48,SAPO-11, and ECR-42, more preferably the dewaxing catalyst is ZSM-48.

[0027] The effective pore size as discussed above is important to thepractice of the invention, not all 10 member ring molecular sieveshaving such effective pore sizes are advantageously usable in thepractice of the present invention. Indeed, it is essential that the mostpreferred intermediate pore size molecular sieve catalysts used in thepractice of the present invention have a very specific pore shape andsize as measured by X-ray crystallography. The intracrystalline channelsmust be parallel and must not interconnect. Such channels areconventionally referred to as 1-D diffusion types or more shortly as 1-Dpores. The classification of intrazeolite channels as 1-D, 2-D and 3-Dis set forth by R. M. Barrer in Zeolites, Science and Technology, editedby F. R. Rodgrigues, L. D. Rollman and C. Naccache, NATO ASI Series,1984 which classification is incorporated in its entirety by reference(see particularly page 75).

[0028] Upon careful examination of the intermediate pore size zeolites,however, it has been found that not all of them are efficient as acatalyst for isomerization of a paraffin-containing feedstock. Theintermediate pore size zeolites forming part of the present inventionare those, which in addition to having the correct pore size, are alsounidirectional. Such 10 member ring, unidirectional zeolites includeZSM-22, ZSM-23, ZSM-35, ZSM-48, and materials isostructural with theseas defined in Atlas of Zeolite Structure Types by S. M. Mier and D. H.Olson., Third Revised Edition, 1992.

[0029] The molecular sieves used herein may also be combined with asuitable porous binder or matrix material. Non-limiting examples of suchmaterials include active and inactive materials such as clays, silica,and/or metal oxides such as alumina. Non-limiting examples of naturallyoccurring clays that can be composited include clays from themontmorillonite and kaolin families including the subbentonites, and thekaolins commonly known as Dixie, McNamee, Georgia, and Florida clays.Others in which the main mineral constituent is halloysite, kaolinite,dickite, nacrite, or anauxite may also be used. The clays can be used inthe raw state as originally mixed or subjected to calcination, acidtreatment, or chemical modification prior to being combined with themedium pore zeolite.

[0030] The dewaxing catalyst contained in the third reaction stage alsocomprises at least one amorphous material having at least one activemetal hydrogenation component dispersed thereon. These amorphousmaterials can be any of the typical amorphous materials such as thosecomprising a refractory metal oxide support base (e.g., alumina,silica-alumina, zirconia, titanium, etc.) on which has been deposited acatalytically active hydrogenation metal selected from at least one ofGroup VI B, Group VII B, Group VIII metals and mixtures thereof,preferably Group VIII, more preferably noble Group VIII, most preferablyPt or Pd. The amorphous material can optionally include a promoter ordopant such as halogen, phosphorous, boron, yttria, magnesia, etc.,preferably halogen, yttria or magnesia, most preferably fluorine. Thecatalytically active metals are present in the range 0.1 to 5 wt. %,preferably 0.1 to 3 wt. %, more preferably 0.1 to 2 wt. %, mostpreferably 0.1 to 1 wt. %. The promoters and dopants are used to controlthe acidity of the isomerization catalyst. Thus, when the amorphousmaterial is a base material such as alumina, acidity is imparted to theresultant catalyst by addition of a halogen, preferably fluorine. When ahalogen is used, preferably fluorine, it is present in an amount in therange 0.1 to 10 wt. %, preferably 0.1 to 3 wt. %, more preferably 0.1 to2 wt. % most preferably 0.5 to 1.5 wt. %. Similarly, if silica-aluminais used as the amorphous material, acidity can be controlled byadjusting the ratio of silica to alumina or by adding a dopant such asyttria or magnesia which reduces the acidity of the silica-alumina basematerial as taught on U.S. Pat. No. 5,254,518 (Soled, McVicker, Gates,Miseo).

[0031] The amorphous material may also be a crystalline mesoporousmaterial belonging to the M41 S class or family of catalysts. The M41 Sfamily of catalysts are crystalline mesoporous materials having highsilica contents whose preparation is further described in J. Amer. Chem.Soc., 1992, 114, 10834. Examples included MCM-41, MCM-48 and MCM-50. Apreferred member of this class is MCM-41 whose preparation is describedin U.S. Pat. No. 5,098,684. MCM-41 is characterized by having ahexagonal crystal structure with a unidimensional arrangement of poreshaving a cell diameter greater than 13 Angstroms. The physical structureof MCM-41 is like a bundle of straws wherein the opening of the straws(the cell diameter of the pores) ranges from 13 to 100+Angstroms. MCM-48has a cubic symmetry and is described for example is U.S. Pat. No.5,198,203 whereas MCM-50 has a lamellar structure and is described inU.S. Pat. No. 5,246,689.

[0032] The catalysts contained in the first, second and third reactionstage can be placed in one or more reactors or reaction zones each ofwhich can comprise one or more catalyst beds of the same, or adifferent, catalyst. Although other types of catalyst beds can be used,fixed catalyst beds are preferred.

[0033] As stated above, at least a portion of the second stage effluentis contacted with the presently described dewaxing catalyst underconditions effective for producing at least one lube oil basestock.These effective conditions typically include temperatures between about200° C. to 400° C., preferably 250° to 380° C. and most preferably 300°C. to 350° C., pressures between about 500 to 5000 psig, preferablyabout 1000 to about 2000 psig, hydrogen gas treat rate of 500 to 10,000SCF H₂/bbl, preferably 2,000 to 5,000 SCF H₂/bbl, and a LHSV of 0.5 to 5V/V/hr, preferably 1 to 2 V/V hr.

[0034] The at least one lube oil basestock produced by the process ofthe present invention comprises at least about 75 wt. % of iso-paraffinsbut has a unique structural character. Basically, the basestock has a“Free Carbon Index” (or FCI) typically lower than about 12, preferablyin the range of about 4 to about 12, more preferably less than 10. Theterm “Free Carbon Index” is a measure of the number of carbons in aniso-paraffin that are located at least 4 carbons from a terminal carbonand more than 3 carbons away from a side chain. The FCI of anisoparaffin can be determined by measuring the percent of methylenegroups in an isoparaffin sample using ¹³C NMR (400 megahertz);multiplying the resultant percentages by the calculated average carbonnumber of the sample determined by ASTM Test method 2502 and dividing by100. A further criteria which differentiates these materialsstructurally from poly alpha olefins is the branch length.Interestingly, in the basestocks of this invention, at least 75% of thebranches, as determined by NMR, are methyls and the population of ethyl,propyl and butyls, etc., fall sharply with increasing molecular weightto the point where no more than 5% are butyls. Typically the ratio of“free carbons” to end methyl is in the range of 2.5 to 4.0.Additionally, the basestocks of this invention typically have, onaverage, from 2.5 to 4.5 side chains per molecule.

[0035] In contrast, polyalpha-olefin (PAO) basestocks have fewer (aboutone) and longer branches or side chains. Indeed the ratio of “freecarbons” to end methyl ranges from 1.1 to 1.7.

[0036] The FCI is further explained as follows. The basestock isanalyzed by ¹³C NMR using a 400 MHz spectrometer. All normal paraffinswith carbon numbers greater than Cg have only five non-equivalent NMRadsorptions corresponding to the terminal methyl carbons (a) methylenesfrom the second, third and forth positions from the molecular ends (β,γ, and δ respectively), and the other carbon atoms along the backbonewhich have a common chemical shift (ε). The intensities of the α, β, γand δ are equal and the intensity of the ε depends on the length of themolecule. Similarly the side branches on the backbone of an iso-paraffinhave unique chemical shifts and the presence of a side chain causes aunique shift at the tertiary carbon (branch point) on the backbone towhich it is anchored. Further, it also perturbs the chemical siteswithin three carbons from this branch point imparting unique chemicalshifts (α′, β′, and γ′).

[0037] The Free Carbon Index (FCI) is then the percent of ε methylenesmeasured from the overall carbon species in the ¹³C NMR spectra of the abasestock, divided by the average carbon Number of the basestock ascalculated from ASTM method 2502, divided by 100.

[0038] Even after very low conversion levels (<10%), the value of εfalls by nearly 50% and there is a large increase in the side chainfraction, larger in fact than that observed in a product that has beenseverely isomerized (>70% conversion to 370° C.-) and solvent dewaxed.The increase in sidechains is almost exclusively in methyl sidechains.There is a much larger percentage of terminal end groups and thedistinction between a methyl at the second or third carbons from the enddrops significantly. Roughly 35% of the added sidechains have been addedto the last four terminal carbons.

[0039] As stated above, another embodiment of the instant inventioninvolves combining the second and third reaction stage to form a singlesecond reaction stage containing a catalyst system. The catalyst systemof this reaction stage comprises at least one first catalyst selectedfrom amorphous hydroisomerization catalysts and at least one secondcatalyst selected from hydrodewaxing catalyst comprising at least onemolecular sieve and an amorphous material having at least one activemetal hydrogenation component dispersed thereon. The catalyst system canbe placed in one or more reactors or reaction zones each of which cancomprise one or more catalyst beds of the same, or a different,catalyst. Although other types of catalyst beds can be used, fixedcatalyst beds are preferred. It is more preferred that the at least onefirst catalyst and the at least one second catalyst of the presentcatalyst system be in the same reaction vessel in a stacked bedarrangement. Interstage cooling or heating between reactors or reactionzones, or between catalyst beds in the same reactor, can be employed. Inthis manner, optimum reaction temperatures can be more easilymaintained. In this embodiment, at least a portion of the hydrotreeatedfeed is contacted with the catalyst system under those conditionsdescribed above as effective hydrodewaxing conditions to produce atleast one lubricating oil basestock. 2 [0035] In one embodiment of theinstant invention, the catalyst system described above is arranged insuch a manner that when at least a portion of the hydrotreated feedcontacts the catalyst system, it contacts the second catalyst first. Indescribing this embodiment, the inventors hereof find it useful to referto the one or more fixed bed reactors or reaction zones each, which cancomprise one or more catalyst beds of the first catalyst, as R1, and theone or more fixed bed reactors or reaction zones each, which cancomprise one or more catalyst beds of the second catalyst, as R2. Thus,in this embodiment, the at least a portion of the hydrotreated feedwould contact R2 first, thence R1.

[0040] It should be noted that the present catalyst system and processconfigurations provide superior performance over processes utilizingmixed, mixed powder pelletized catalysts, etc. By providing a separatehydroisomerization reaction stage and a separate hydrodewaxing stage,the practitioner is allowed to control process variables within thesereaction stages to provide a process that is better suited for theparticular feed processed. Thus, by placing catalysts, reaction zones,beds, etc. in the manner described herein, the practitioner of thepresently claimed process is given greater control over the reactionintended. For example, the practitioner of the instantly claimedprocess, if desired, could process a feedstream over thehydroisomerization catalyst for a longer period of time, under moresevere conditions, etc., while not having to process the feed over thehydrodewaxing catalyst under the same conditions. However, if thehydroisomerization catalyst and the hydrodewaxing catalyst were a mixed,mixed powder pelletized catalyst, etc. the practitioner would lack thiscontrol. In particular, conditions in the hydroisomerization reactor canbe tailored to control the extent of boiling range conversion of aparticular feed stream to target the appropriate viscosity/volatilityrequired for the basestock, a property not readily controlled in thehydrodewaxing reactor. For example, feeds with wider boiling range mayrequire more severe hydroisomerization conditions to achieve sufficientconversion of the higher boiling species needed to produce a basestockwith both low volatility and low viscosity. Thus, the presently claimedinvention provides an advantage over processes utilizing mixed, mixedpowder pelletized catalyst, etc. in that the process can be particularlytailored for any feed to provide a product in good yield with excellentviscometric properties, low volatility as well as good low temperatureproperties

[0041] The above description is directed to several embodiments of thepresent invention. Those skilled in the art will recognize that otherembodiments that are equally effective could be devised for carrying outthe spirit of this invention.

1. A method for producing a lube oil lube basestock from a lube oilboiling range feedstream containing at least about 50 wt. % wax, and atleast one polar compound containing sulfur or nitrogen comprising: a)contacting the lube oil boiling range feedstream with a hydrotreatingcatalyst in a first reaction stage operated under conditions effectiveat removing at least a portion of the at least one polar compound fromsaid lube oil boiling range feedstream to produce a hydrotreated feed;b) contacting at least a portion of said hydrotreated feed with anamorphous hydroisomerization catalyst in a second reaction stageoperated under effective hydroisomerization conditions to produce asecond stage effluent; and c) contacting at least a portion of saidsecond stage effluent with a hydrodewaxing catalyst in a third reactionstage operated under conditions effective for producing at least onelube oil basestock wherein said catalyst comprises at least onemolecular sieve and at least one amorphous material having at least oneactive metal hydrogenation component dispersed thereon.
 2. The methodaccording to claim 1 wherein said lube oil boiling range feedstream isderived from a mineral or synthetic source or mixtures thereof.
 3. Themethod according to claim 2 wherein said hydrotreating catalyst isselected from bulk and conventional hydrotreating catalysts comprisingat least one Group VI metal and at least one Group VIII metal.
 4. Themethod according to claim 3 wherein said hydrotreating catalyst isselected from Nebula™, RT-721, KF-840, KF-848, DN 190, Sentinel™.
 5. Themethod according to claim 4 wherein said conditions effective atremoving at least a portion at least one contaminant from said lube oilboiling range feedstream include temperatures of from 150 to 400° C., ahydrogen partial pressure of from 1480 to 20786 kPa (200 to 3000 psig),a space velocity of from 0.1 to 10 liquid hourly space velocity (LHSV),and a hydrogen to feed ratio of from 89 to 1780 m³/m³ (500 to 10000scf/B), preferably 178 to 890 m³/m³.
 6. The method according to claim 5wherein said amorphous hydroisomerization catalysts contained in saidsecond stage comprises a porous refractory metal oxide support and acatalytic component selected from at least one of Group VIB, Group VIIB,Group VIII metals, and mixtures thereof.
 7. The method according toclaim 5 wherein said hydrodewaxing catalyst comprises at least onemolecular sieve and at least one amorphous material comprising amesoporous support.
 8. The method according to claim 6 wherein saidamorphous material of said dewaxing catalyst further comprises at leastone promoter or dopant selected from the group consisting of halogen,phosphorous, boron, yttria, rare-earth oxides and magnesia preferablyhalogen, yttria, magnesia.
 9. The method according to claim 7 whereinsaid effective hydroisomerization conditions are selected such that thewax content of said hydrotreated feed is reduced to below about 40 wt.%, based on the hydrotreated feed.
 10. The method according to claim 1wherein said molecular sieve is selected from, ZSM-22, ZSM-23, ZSM-35,ZSM-48, ZSM-57, SSZ-31, SAPO-11, SAPO-31, SAPO-41, MAPO-11, ECR-42,synthetic Ferrierites, and mixtures thereof.
 11. The method according toclaim 1 wherein said at least one molecular sieve is selected from 10member ring, unidirectional, inorganic oxide molecular sieves.
 12. Themethod according to claim 10 wherein said molecular sieve is combinedwith a suitable porous binder or matrix material.
 13. The methodaccording to claim 10 wherein said at least one active metalhydrogenation component of said amorphous material of said hydrodewaxingcatalyst is selected from Group VIB, Group VIIB, Group VIII metals, andmixtures thereof.
 14. The method according to claim 13 wherein saidfirst, second, and third stages comprise one or more reactors orreaction zones each of which comprise one or more catalyst beds thateach contain the same or different catalyst.
 15. The method according toclaim 14 wherein said catalyst beds are selected from fixed beds,fluidized beds, ebullating beds, slurry beds, and moving beds.
 16. Themethod according to claim 18 wherein the amorphous material of saiddewaxing catalyst further comprises a promoter selected from the groupconsisting of halogen, phosphorous, boron, yttria, rare-earth oxides andmagnesia.
 17. The method according to claim 16 wherein the at least onelube oil basestock produced by the process of the present inventioncomprises at least about 75 wt. % of iso-paraffins and has a “FreeCarbon Index” (or FCI) lower than about
 12. 18. The method according toclaim 1 wherein said second and third reaction stages are combined toform one second reaction stage wherein at least a portion of saidhydrotreated feed is contacted with a catalyst system in a secondreaction stage operated under conditions effective at producing at leastone lube oil boiling range basestock wherein said catalyst systemcomprises at least one first catalyst selected from amorphoushydroisomerization catalyst and at least one second catalyst selectedfrom hydrodewaxing catalysts comprising at least one molecular sieve andan amorphous material having at least one active metal hydrogenationcomponent dispersed thereon.
 19. The method according to claim 18wherein said catalyst system is arranged in such a manner that when saidhydrotreated feed contacts said catalyst system, it contacts the secondcatalyst first.
 20. A method for producing a lube oil lube basestockfrom a lube oil boiling range feedstream containing at least about 50wt. % wax, and at least one polar compound containing sulfur or nitrogencomprising: a) contacting the lube oil boiling range feedstream with ahydrotreating catalyst in a first reaction stage operated underconditions effective at removing at least a portion of the at least onepolar compound from said lube oil boiling range feedstream to produce ahydrotreated feed; and b) contacting at least a portion of saidhydrotreated feed with a catalyst system in a second reaction stageoperated under conditions effective at producing at least one lube oilboiling range basestock wherein said catalyst system comprises at leastone first catalyst selected from amorphous hydroisomerization catalystand at least one second catalyst selected from hydrodewaxing catalystscomprising at least one molecular sieve and at least one amorphousmaterial having at least one active metal hydrogenation componentdispersed thereon.
 21. The method according to claim 20 wherein saidcatalyst system is arranged in such a manner that when said at least aportion of said hydrotreated feed contacts said catalyst system, itcontacts the second catalyst first.